One of the current trends in the automobile industry is to lower vehicle weight to help achieve better fuel economy, thus helping to meet fuel economy standards and to offset the higher fuel prices. There are also government regulations with the stated directive of improving fuel economy by meeting more stringent demands such as imposed by Corporate Average Fuel Economy (CAFE) regulations.
Vehicles typically include fairly heavy components, including fascias making the bumper of the vehicle a target area for weight reduction. Fascias are traditionally made from a thermoplastic material using a traditional single injection molding process. Using lower density substrate materials in the traditional injection molding process is an alternative in a known attempt to reduce part weight. Using blowing agents in a single injection process is another known alternative. Using single injection molding with lower density material or blowing agents presents several manufacturing concerns related to the material, performance, and process. It is also known to reduce wallstock/part thickness. Thermoplastic composite materials used in fascia applications may also have difficulty meeting customer performance specifications.
Another concern with the manufacture of fascias is that typical coinjected fascias have one material in the coinjected part that is significantly stiffer than the other material, but this will not necessarily reduce weight and retain desired surface appearance, properties and characteristics. There are also read through areas which must be dealt with by design modifications or expensive processes. If a part is molded with too little thermoplastic skin material and with too much thermoplastic core material the core material “breaks out” of the skin material. The breakout results in visible core material at the part surface.
Accordingly, there exists a need for a molded vehicle component which is lightweight and retains desirable surface appearance, properties and characteristics, while being cost effective relative to conventional molded components and methods of manufacturing same.